Many watches and other timing devices have incorporated other features in addition to a time-keeping function. An example is a running watch, which can tell the runner, at any point in time, the total time of the run and also the time the runner has spent in completing the last interval, which can be a section in a range of distance that the runner is to cover.
U.S. Pat. No. 5,476,427 describes a pace display device that calculates the average and actual pace to cover a specified distance based on a number of steps per unit time. It calculates the difference between the actual and average (based on prior tests) and displays the difference to inform the individual of their performance relative to the average pace.
U.S. Pat. No. 5,301,154 describes a time calculating device that calculates a time for a user of the device to run a distance and provides an estimated “goal time”. The estimation is based on the age and heart rate of the runner and a comparison of these data with stored the age and heart rate data in two previous runs of the same distance.
U.S. Pat. No. 5,404,341 provides an estimated time to complete one interval or lap based on a standard lap time.
U.S. Pat. No. 3,598,306 discloses a time-speed instrument that provides computation and/or display of travel time, estimated time of arrival, actual time of arrival, speed, elapsed time, distance traveled and current time. This device provides the estimated time of arrival based on user input of known variables (e.g., start time, speed to cover entire distance, and length of distance) into a manual, logarithmic clock mechanism that utilizes overlaying “cards” to calculate the various data.
In many situations, data associated with a runner's previous runs are either not available or cannot be used to predict the runner's performance in a current run. Therefore, there is a need for a timing device that computes a runner's estimated time of arrival based on his performance in part of all of the distance that the runner has covered in the current run.